Cannabis smoke and plant extracts present extremely complex mixtures of compounds with different chemical properties. In order to explain various toxicological and pharmacological effects of cannabis, a more extensive knowledge of its chemistry is needed. The present works aim at non-destructive fractionation of cannabis smoke into discrete chemical groups, the separation of individual components, and their total chemical characterization. The fractions under investigation include bases, acids/phenols, and polar and non-polar neutrals. Glass capillary gas chromatography provides a highly efficient compound separation, whereas the electron-impact and chemical ionization mass spectroscopy are used for identification. Less volatile components are analyzed by high-performance liquid chromatography. The chemical composition of cannabis is being correlated with its toxicological and pharmacological properties. Tobacco smoke is used as a "baseline" material for both compositional and biological investigations.